1. Field of the Invention
The invention relates to an optical module and a display module, and particularly relates to a front light module and a display module.
2. Description of Related Art
Generally, a reflective display having a front light module is designed to dispose the front light module above a display module, and dispose a light source at a side surface of a light guide plate (LGP). Thus, light emitted by the light source may travel in total internal reflection in the light guide plate. The total internal reflection is canceled by using microstructures, and the light is refracted toward the display module, so as to convert the light source into a surface light source with a uniform optical distribution. The light refracted toward the display module may then be reflected by the display module and transmitted to the viewer.
A conventional front light module of the reflective display includes a light source, a light guide plate, an optical clear adhesive (OCA), and an anti-glare film (AG film). The light guide plate is attached to the display module and the anti-glare film through the optical clear adhesive. Generally, the light source used in the front light module is a non-continuous light source, such as a plurality of light emitting diodes (LEDs) that are independently disposed. Since the light sources are in a discontinuous distribution, the reflective display may have uneven brightness at a light incident side, namely a hot spot phenomenon.
A conventional way to deal with the hot spot is to manufacture a microstructure (such as a serration microstructure) on the light incident surface of the light guide plate or adjust a screen dot density of the light guide plate. However, due to the decrease in the number of light sources and the increase in the display size in the applications of the reflective display, such method has its limitation. Besides, as the screen dot density of the light guide plate increases, the precision requirement on the alignment with respect of the light sources is consequently increased significantly. Thus, assembling properties of the reflective display are limited.